This research is designed to test the possibility of detecting cancer and of following the course of the disease by measuring the amounts of a large number of compounds in physiological fluids by chromatographic methods, followed by computerized procedures for recognizing patterns. If these techniques prove to be useful, they would make some contribution to diagnosis and evaluation of therapy in cancer. Also, the chemical nature of the significant substances found in the body fluids might make some contribution to fundamental research on cancer. Our work includes studies being carried out on a test for a cancer pattern in subjects with melanoma, the accumulation of sets of samples from subjects with other kinds of cancer, and the study of samples of urine from hairless mice in which skin cancer is being induced by ultra-violet radiation.